1. Field of the Invention
The present invention relates generally to hose and fitting assemblies, and in particular to a fitting spot-welded to a section of flexible, spiral-wound metal piping or hose.
2. Description of the Related Art
Piping, tubing and conduits are used to convey a variety of different types of matter, including solid and semi-solid bulk material (e.g. grain, sand, powder etc.), liquids and gases. End fittings are commonly attached to the ends of such piping, tubing and conduits for connection to the material handling equipment, other piping, receptacles, etc. Various methods have heretofore been proposed for attaching such fittings to piping, tubing, conduits and the like. For example, hose clamps are often utilized for connecting rubber hoses to various fittings. Adhesives can also be employed. Connections between metal piping and metal fittings can be made by welding and by various mechanical fasteners, such as rivets.
Flexible metal piping or hose is used for a variety of material handling applications, including conveying dry bulk materials such as solids, semi-solids, etc. Such flexible piping can be formed by spiral-winding continuous bands and interlocking the leading and trailing edges thereof. The interlocked seams thereof can permit flexure of the piping while providing relatively tight seams which are semi-pervious or impervious to most materials. Various methods have heretofore been employed for attaching fittings to such flexible metal piping. For example, annular welds have been formed around the piping ends and the fitting. However, such circular weldments can be expensive and time consuming, or can require special equipment for rotation of the welding equipment relative to the piping or for rotation of the piping relative to the welding equipment.
Spot-welding typically involves the placement of an electrically-charged electrode or welding wire against a workpiece with an opposite electrical charge. Spot-welding in commonly utilized for attaching two pieces of sheet metal together at point locations. Automated spot-welding equipment is available, and can utilize robotics for automated production of spot-welded items.
Heretofore there has not been available a method or apparatus for spot welding fittings on flexible metal hose or piping sections with the advantages and features of the present invention.